Semiconductor device, circuit board, and electronic instrument

ABSTRACT

A semiconductor device with a package size close to its chip size is, apart from a stress absorbing layer, such as to effectively absorb thermal stresses. A semiconductor device ( 150 ) has a semiconductor chip provided with electrodes ( 158 ), a resin layer ( 152 ) forming a stress relieving layer provided on the semiconductor chip, wiring ( 154 ) formed from the electrodes ( 158 ) to over the resin layer ( 152 ), and solder balls ( 157 ) formed on the wiring ( 154 ) over the resin layer ( 152 ); the resin layer ( 152 ) is formed so as to have a depression ( 152   a ) in the surface, and the wiring ( 154 ) is formed so as to pass over the depression ( 152   a ).

This is a Division of application Ser. No. 11/480,846 filed Jul. 6,2006, which in turn is a Division of Ser. No. 10/463,470 filed Jun. 18,2003 (now U.S. Pat. No. 7,183,189), which in turn is a Continuation ofapplication Ser. No. 09/666,406 (now U.S. Pat. No. 6,608,389), which inturn is a Continuation of application Ser. No. 09/117,526 (now U.S. Pat.No. 6,255,737), which is the National Stage of International ApplicationNo. PCT/JP97/04438 filed Dec. 4, 1997. The entire disclosure of theprior applications is hereby incorporated by reference herein in itsentirety.

TECHNICAL FIELD

The present invention relates to a semiconductor device and method ofmaking the same, a circuit board, and an electronic instrument, and inparticular relates to a semiconductor device having a package size closeto the chip size and a method of making the same, a circuit board, andan electronic instrument.

BACKGROUND ART

To pursue high-density mounting in semiconductor devices, bare chipmounting is the ideal. However, for bare chips, quality control andhandling are difficult. In answer to this, CSP (chip size package), orpackages whose size is close to that of the chip, have been developed.

Of the forms of CSP semiconductor device developed, one form has aflexible substrate provided, patterned on the active surface of thesemiconductor chip, and on this flexible substrate are formed aplurality of external electrodes. It is also known to inject a resinbetween the active surface of the semiconductor chip and the flexiblesubstrate, in order to absorb the terminal stress.

However, in cases where resin alone is insufficient to absorb thethermal stress, another means is required.

The present invention has as its object the solution of the abovedescribed problems, and this object subsists in the provision of asemiconductor device and method of making the same, a circuit board, andan electronic instrument such that the package size is close to the chipsize, and such that apart from the stress absorbing layer, thermalstress can be effectively absorbed.

DISCLOSURE OF INVENTION

The method of making a semiconductor device of the present inventioncomprises:

a step of providing a wafer on which are formed electrodes,

a step of providing a first stress relieving layer on the wafer avoidingat least a part of the electrodes;

a step of forming a first conducting portion over the first stressrelieving layer from the electrodes;

a step of forming external electrodes connected to the first conductingportion on the first stress relieving layer; and a stop of cutting thewafer into individual pieces, and

wherein in at least one of the step of providing the first stressrelieving layer and the step of forming the first conducting portion aconstruction is formed which increases the relief of stress.

According to the aspect of the present invention, since the conductingportions and external electrodes are formed over a stress relievinglayer, this obviates the need for a substrate such as a patterned filmwith preformed external electrodes.

Besides, since the conducting portions between the electrodes and theexternal electrodes can be formed freely according to the requirementsof the design, the layout of the external electrodes can be determinedregardless of the layout of the electrodes. As a result, withoutchanging the circuit design of the elements formed on the wafer, varioussemiconductor devices with the external electrodes in differentpositions can easily be fabricated.

Furthermore, according to the aspect of the present invention, after thestress relieving layer, conducting portions and external electrodes areformed on the wafer, the wafer is cut, to obtain individualsemiconductor devices. As a result, the formation of the stressrelieving layer, conducting portions and external electrodes on a largenumber of semiconductor devices can be carried out simultaneously, andthe fabrication process can be simplified.

As the construction which increases the relief of stress, a depressionmay be formed on the surface of the first stress relieving layer, andthe first conducting portion is formed to pass over the depression.

By this means, since the conducting portion is formed to be bent in adirection intersecting to the surface of the stress relieving layer, thestress can be absorbed by a variation of the bending condition, andwiring breaks can be prevented.

As the construction which increases the relief of stress, in the stop offorming the first conducting portion, the first conducting portion maybe formed so as to be bent in a direction of a horizontal plane on thefirst stress relieving layer.

There may further be a step of inserting an elastic body over the firstconducting portion positioned at the depression. By means of thiselastic body, stress can be further absorbed.

There may further be a step of providing a second stress relieving layerand a second conducting portion connected to the first conductingportion on the first stress relieving layer on which the firstconducting portion is formed.

By this means, the stress relieving layer is formed as a plurality oflayers, and the stress is thereby even more easily distributed.

At least one of the first conducting portion and the second conductingportion may be formed in planar form, to have its larger planar extentthan its thickness.

By this means, since a signal is transmitted in the vicinity of a planarground potential, an ideal transmission path is obtained.

A second stress relieving layer and a second conducting portion may beprovided on the first stress relieving layer on which the firstconducting portion is formed;

a third stress relieving layer and a third conducting portion may beprovided on the second stress relieving layer on which the secondconducting portion is formed; and

the second conducting portion may be formed in linear form, and thefirst and third conducting portions may be formed in planar form, tohave their larger planar extent than that of the second conductingportion.

By this means, since the linearly formed second conducting portion issandwiched between a pair of planar conducting portions, it is coveredby surrounding wires at ground potential. In this way a constructionsimilar to coaxial cable is obtained, and the signal passing through thesecond conducting portion is less susceptible to the influence of noise.

A pair of wires at ground potential may be formed parallel to and onboth side of the first conducting portion.

By this means, since the linearly formed first conducting portion issandwiched between a pair of wires, it is covered by surrounding wiresat ground potential. In this way a construction similar to coaxial cableis obtained, and the signal is less susceptible to the influence ofnoise.

The semiconductor device of the present invention comprises:

a semiconductor chip having electrodes;

a first stress relieving layer provided on the semiconductor chip so asto avoid at least a part of the electrodes;

a first conducting portion formed from the electrodes over the firststress relieving layer; and

external electrodes formed on the first conducting portion positionedabove the first stress relieving layer, and

wherein the first stress relieving layer is formed to have a depressionon its surface, and the first conducting portion is formed to pass overthe depression.

By this means, since the conducting portion is formed to be bent in adirection intersecting to the surface of the stress relieving layer, thestress can be absorbed by a variation of the bending condition, andwiring breaks can be prevented.

On the first conducting portion positioned over the depression, anelastic body may be provided so as to fill the depression.

The first conducting portion may be formed to be bent over the firststress relieving layer.

The first conducting portion may be formed to have a bellows form.

A second stress relieving layer and a second conducting portionconnected to the first conducting portion may be provided on the firststress relieving layer on which the first conducting portion is formed.

By this means, the stress relieving layer is formed as a plurality oflayers, and the stress is thereby even more easily distributed.

One of two conducting portions consisting of the first conductingportion and the second conducting portion may be, formed in a linearform, and the other may be formed in planar form, to have its largerplanar extent than that of the linear conducting portion.

The planar conducting portion may be at ground potential, and a signalis input in the linear conducting portion.

The semiconductor device may further comprises;

a second stress relieving layer and a second conducting portion providedon the first stress relieving layer on which the first conductingportion is formed; and

a third stress relieving layer and a third conducting portion providedon the second stress relieving layer on which the second conductingportion is formed, and

wherein the second conducting portion may be formed in linear form, andthe first and third conducting portions are formed in planar form tohave its larger planar extent than that of the second conductingportion.

By this means, since the linearly formed second conducting portion issandwiched between a pair of planar conducting portions, it is coveredby surrounding wires at ground potential. In this way a constructionsimilar to coaxial cable is obtained, and the signal passing through thesecond conducting portion is less susceptible to the influence of noise.

There may further be a pair of wires at ground potential formed parallelto and on both sides of the first conducting portion.

By this means, since the linearly formed first conducting portion issandwiched between a pair of wires, it is covered by surrounding wiresat ground potential. In this way a construction similar to coaxial cableis obtained, and the signal is less susceptible to the influence ofnoise.

There may further be a protective film on a surface of the semiconductorchip opposite to a surface having the electrodes.

There may further be a radiator on a surface of the semiconductor chipopposite to a surface having the electrodes.

On the circuit board of the present invention is mounted the abovedescribed semiconductor device.

The electronic instrument of the present invention has this circuitboard.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A to 1E illustrate a method of making a semiconductor devicebeing a basic of the present invention;

FIGS. 2A to 2E illustrate the method of making a semiconductor devicebeing a basic of the present invention;

FIGS. 3A to 3D illustrate the method of making a semiconductor devicebeing a basic of the present invention;

FIGS. 4A to 4C illustrate the method of making a semiconductor devicebeing a basic of the present invention;

FIG. 5 is a plan view showing the semiconductor device being a basic ofthe present invention;

FIGS. 6A to 6C illustrate the method of making a semiconductor devicebeing a basic of the present invention;

FIGS. 7A to 7C illustrate the method of making a semiconductor devicebeing a basic of the present invention;

FIGS. 8A to 8D illustrate the method of making a semiconductor devicebeing a basic of the present invention;

FIGS. 9A to 9D illustrate the method of making a semiconductor devicebeing a basic of the present invention;

FIG. 10 illustrates the method of making a semiconductor device being abasic of the present invention;

FIGS. 11A to 11D illustrate the method of making a semiconductor devicebeing a basic of the present invention;

FIGS. 12A to 12C illustrate the method of making a semiconductor devicebeing a basic of the present invention;

FIGS. 13A to 13D illustrate the method of making a semiconductor devicebeing a basic of the present invention;

FIGS. 14A to 14D illustrate a first embodiment of the semiconductordevice of the present invention;

FIG. 15 illustrates a second embodiment of the semiconductor device;

FIG. 16 illustrates a third embodiment of the semiconductor device;

FIGS. 17A and 17B illustrate the third embodiment of the method ofmaking a semiconductor device;

FIGS. 18A and 18B illustrate the third embodiment of the method ofmaking a semiconductor device;

FIGS. 19A and 19B illustrate the third embodiment of the method ofmaking a semiconductor device;

FIGS. 20A and 20B illustrate the third embodiment of the method ofmaking a semiconductor device;

FIG. 21 shows an example of the present invention applied to anelectronic component for surface mounting;

FIG. 22 shows an example of the present invention applied to anelectronic component for surface mounting;

FIG. 23 shows an example in which a protective layer is formed on asemiconductor device to which the present invention is applied;

FIG. 24 shows an example in which a radiator is provided on thesemiconductor device to which the present invention is applied;

FIG. 25 shows a circuit board on which is mounted an electroniccomponent fabricated by application of the method of the presentinvention; and

FIG. 26 shows an electronic instrument provided with a circuit board onwhich is mounted an electronic component fabricated by application ofthe method of the present invention.

BEST MODE FOR CARRYING OUT THE INVENTION

Before the description of the embodiments of the present invention, thebasic art is described.

(First Basic Art)

FIG. 5 is a plan view of a semiconductor device of this basic art. Thissemiconductor device is classified as a so-called CSP, and has wires 3formed extending toward the center of an active surface 1 a fromelectrodes 12 of a semiconductor chip 1, and on each wire 3 is providedan external electrode 5. All of the external electrodes 5 are providedon a stress relieving layer 7, so that when mounted on a circuit board(not shown in the drawings) the stresses can be relieved. Besides, overthe external electrodes 5, a solder resist layer 8 is formed as aprotective film.

It should be noted that as shown in this drawing the external electrodes5 are provided not on the electrodes 12 of the semiconductor chip 1, butin the active region (the region in which the active elements areformed) of the semiconductor chip 1. By providing the stress relievinglayer 7 in the active region, and further positioning (bringing in) thewires 3 within the active region, the external electrodes 5 can beprovided within the active region. As a result, when laying out theexternal electrodes 5, the active region, that is to say, a region of aparticular surface can be provided, and thus the degree of freedom forpositioning the external electrodes 5 is greatly increased.

By bending the wires 3 on the stress relieving layer 7, the externalelectrodes 5 can be provided in a lattice. Besides, at the junction ofthe electrodes 12 and wires 3 the size of the electrodes 12 and the sizeof the wires 3 are such that:

wires 3<electrodes 12

but it is preferable that:

electrodes 12≦wires 3

In particular, in the case that:

electrodes 12<wires 3

not only is the resistance of the wires 3 reduced, but also, since thestrength is increased, broken wires are prevented.

FIGS. 1A to 4C illustrate the first basic art of the method of making asemiconductor device, and correspond to the section along the line I-Iin FIG. 5.

First, by well-known techniques, electrodes 12 and other elements areformed on a wafer 10. It should be noted that in this example, theelectrodes 12 are formed of aluminum. As examples of other materials forthe electrodes 12 may equally be used aluminum alloy materials (forexample, aluminum-silicon or aluminum-silicon-copper, or the like).

Besides, on the surface of the wafer 10 is formed a passivation film(not shown in the drawings) being an oxidized film or the like, forpreventing chemical changes. The passivation film is formed not only toavoid the electrodes 12, but also to avoid the scribing line to whichdicing is carried out. By not forming the passivation film on thescribing line, during the dicing operation the generation of dust can beavoided, and the occurrence of cracks in the passivation film can alsobe prevented.

As shown in FIG. 1A, on the water 10 having the electrodes 12 aphotosensitive polyimide resin is applied (using, for example, the spincoating method) to form a resin layer 14. The resin layer 14 has athickness preferably in the range 1 to 100 μm, and more preferably ofaround 10 μm. It should be noted that in the spin coating method, sincethere is a large quantity of polyimide resin wasted, a device may beused which employs a pump to eject a strip of polyimide resin. As anexample of such a device may be given, for example, the FASultra-high-density ejection coating system (see U.S. Pat. No. 4,696,885)manufactured by the FAS company.

As shown in FIG. 1B, in the resin layer 14 are formed contact holes 14 afor the electrodes 12. Specifically, by means of exposure, development,and firing processes, the polyimide resin in the vicinity of theelectrodes 12 is removed, whereby the contact holes 14 a are formed inthe resin layer 14. It should be noted that in this figure, when thecontact holes 14 a are formed, absolutely no region is left in which theresin layer 14 overlaps the electrodes 12. By leaving absolutely none ofthe resin layer 14 on the electrodes 12, there is the advantage that inthe subsequent stages in which wiring and other metallic components areprovided, the electrical contact is satisfactory, but the constructionis not necessarily restricted in this way. That is to say, even in aconstruction in which on the outer periphery of the electrodes 12 theresin layer 14 is applied, if holes are provided so that a part of theelectrodes 12 is exposed, this will adequately achieve the objective. Inthis case, the number of bends in the wiring layer is reduced, and as aresult, a loss of wiring reliability due to broken wires and the likecan be prevented. Here, the contact holes 14 a have a taper. As aresult, at the edges where the contact holes 14 a are formed, the resinlayer 14 is formed with an inclination. Such a formation can be achievedby selection of the conditions of exposure and development. Furthermore,by treatment of the electrodes 12 by a plasma of O₂, even if a smallamount of the polyimide resin is left remaining on the electrodes 12,the polyimide resin can be completely removed. The resin layer 14 formedin this way forms the stress relieving layer in the completedsemiconductor device.

It should be noted that in this example a photosensitive polyimide resinis used as the resin, but a nonphotosensitive resin may equally be used.For example, a material with a stress relieving function having a lowYoung's modulus (not exceeding 1×10¹⁰ Pa) when solidified, such as asilicone denatured polyimide resin, an epoxy resin, or a siliconedenatured epoxy resin, may be used.

As shown in FIG. 1C, a chromium (Cr) layer 16 is formed by sputteringover the whole surface of the wafer 10. The chromium (Cr) layer 16 isformed over both the electrodes 12 and the resin layer 14. Here, thematerial of the chromium (Cr) layer 16 is selected to have good adhesionwith the polyimide forming the resin layer 14. Alternatively, whenresistance to cracks is considered, a ductile metal such as aluminum,alloys of aluminum such as aluminum-silicon and aluminum-copper, alloysof copper (Cu), copper, or gold may be used. If titanium, which hasexcellent moisture resistance, is selected, wire breakages due tocorrosion can be prevented. Titanium also has preferred adhesion withrespect to polyimide, and titanium-tungsten may also be used.

When the adhesion with the chromium (Cr) layer 16 is considered, it ispreferable for the surface of the resin layer 14 of polyimide or thelike to be roughened. For example, by carrying out dry processing with aplasma (O₂, CF₄), or wet processing with an acid or alkali, the surfaceof the resin layer 14 can be roughened.

Besides, since within the contact holes 14 a the edges of the resinlayer 14 are inclined, in this region the chromium (Cr) layer 16 isformed to be similarly inclined. In the semiconductor device which isthe finished product the chromium (Cr) layer 16 forms the wires 3 (seeFIG. 5), and also during the fabrication process serves as a layer toprevent dispersion of the polyimide resin at the time of thereafterforming the layer. It should be noted that the dispersion preventinglayer is not restricted to chromium (Cr) and all of the above-mentionedwiring materials are also effective.

As shown in FIG. 1D, on the chromium (Cr) layer 16, a photoresist isapplied to form a resist layer 18.

As shown in FIG. 1E, by means of exposure, development, and firingprocesses, a part of the resist layer 18 is removed. The remainingresist layer 18, is formed from the electrodes 12 in the direction ofthe center of the resin layer 14. In more detail, the remaining resistlayer 18 is formed so that on the resin layer 14 the portion of theresist layer 18 on one electrode 12 and the portion of the resist layer18 on another electrode 12 are not continuous (are mutuallyindependent).

Next, leaving only the region covered by the resist layer 18 shown inFIG. 1E (that is to say, with the resist layer 18 as a mask), thechromium (Cr) layer 16 is etched, and the resist layer 18 is removed.With this, in these previous processes metal thin film formationtechnology in wafer processing is applied. The chromium (Cr) layer 16thus etched is shown in FIG. 2A.

In FIG. 2A, the chromium (Cr) layer 16 is formed extending from theelectrodes 12 over the resin layer 14. In more detail, the chromium (Cr)layer 16 is formed so as not to connect one electrode 12 to anotherelectrode 12. That is to say, the chromium (Cr) layer 16 is formed insuch a way that the wiring corresponding to each of the electrodes 12can be formed.

As shown in FIG. 2B, above the topmost layer including at least thechromium (Cr) layer 16, a copper (Cu) layer 20 is formed by sputtering.The copper (Cu) layer 20 forms an under-layer for forming externalelectrodes. Alternatively, in place of the copper (Cu) layer 20, anickel (Ni) layer may be formed.

As shown in FIG. 2C, on the copper (Cu) layer 20 is formed a resistlayer 22, and as shown in FIG. 2D, a part of the resist layer 22 isremoved by exposure, development, and firing processes. In this way, asfor the region removed, at least a part of the resist layer 22positioned over the resin layer 14, and over the chromium (Cr) layer 16is removed.

As shown in FIG. 2E, in the region in which the resist layer 22 ispartially removed, a base 24 is formed. The base 24 is formed by copper(Cu) plating, and is such that a solder balls can be formed thereon. Asa result, the base 24 is formed on the copper (Cu) layer 20, and iselectrically connected through this copper (Cu) layer 20 and thechromium (Cr) layer 16 to the electrodes 12.

As shown in FIG. 3A, on the base 24, solder 26 which will form solderballs as the external electrodes 5 (see FIG. 5) is formed as a thickfilm. This thickness is determined by the amount of solder correspondingto the ball diameter required when at a later state the solder balls areformed. The layer of solder 26 is formed by electroplating, printing, orthe like.

As shown in FIG. 3B, the resist layer 22 shown in FIG. 3A is removed,and the copper (Cu) layer 20 is etched. In this way, the base 24 forms amask, the copper (Cu) layer 20 remains only under this base 24 (see FIG.3C). Next, the solder 26 on the base 24 is formed into balls of at leasthemispherical shape by wet-back, making solder balls (see FIG. 3D).

By means of the above process, solder balls are formed as the externalelectrodes 5 (see FIG. 5). Next, processes for achieving the objectivesof preventing the oxidation of the chromium (Cr) layer 16 or the like,of improving moisture resistance in the finished semiconductor device,of providing mechanical protection for the surface, and so forth, arecarried out as shown in FIGS. 4A and 4B.

As shown in FIG. 4A, a photosensitive solder resist layer 28 is formedby application over the whole surface of the wafer 10. Then, by carryingout exposure, development, and firing processes, the portion of thesolder resist layer 28 covering the solder 26 and the neighboring regionis removed. In this way, the remaining solder resist layer 28 acts as afilm for preventing oxidation, and as a protective film in the finishedsemiconductor device, and further forms a protective layer for thepurpose of improving moisture resistance. Next a test for electricalcharacteristics is carried out, and if required, a product number andmanufacturer's name are printed.

Next, dicing is carried out, and as shown in FIG. 4C, individualsemiconductor devices are separated. Here, the dicing position, as willbe clear from a comparison of FIGS. 4B and 4C, is such as to avoid theresin layer 14. As a result, since dicing is carried out only on thewafer 10, problems involved in cutting through a number of layers ofdifferent materials can be avoided. The dicing process is carried out bya conventional method.

With a semiconductor device formed in this way, the resin layer 14 formsa stress relieving layer 7 (see FIG. 5), and therefore stress occurringbecause of differences in coefficients of thermal expansion between acircuit board (not shown in the drawings) and the semiconductor chip 1(see FIG. 5) is alleviated.

According to the above described method of making a semiconductordevice, almost all steps are completed within the stage of waterprocessing. In other words, the step in which the external terminals forconnection to the board on which mounting is to take place is carriedout within the stage of wafer processing, and it is not necessary tocarry out the conventional packaging process, such as an inner leadbonding process and external terminal formation process for eachindividual semiconductor chip, in which individual semiconductor chipsare handled. Besides, when the stress relieving layer is formed, asubstrate such as a patterned film is not required. For these reasons, asemiconductor device of low cost and high quality can be obtained.

In this example, as the resin of the stress relieving layer is used aphotosensitive polyimide resin, but alternatively a nonphotosensitiveresin may also be used. Besides, in this example, there may be two ormore wiring layers. Generally, when layers are superimposed the layerthickness increases, and the wiring resistance can be reduced. Inparticular, when one layer of the wiring is of chromium (Cr), sincecopper (Cu) or gold has a lower electrical resistance than chromium(Cr), a combination makes it possible to reduce the wiring resistance.Alternatively, a titanium layer may be formed on the stress relievinglayer, and on this titanium layer a nickel layer or a layer of platinumand gold may be formed. Besides, two layers, of platinum and gold, mayalso be used for the wiring.

(Second Basic Art)

FIGS. 6A to 7C illustrate the second basic art of the method of making asemiconductor device. This art differs from the first basic art in thesteps in FIG. 3A and subsequent steps, and in the steps up to FIG. 2E isthe same as the first basic art. Therefore, since the wafer 110,electrodes 112, resin layer 114, chromium (Cr) layer 116, copper (Cu)layer 120, resist layer 122, and base 124 shown in FIG. 6A are the sameas the wafer 10, electrodes 12, resin layer 14, chromium (Cr) layer 16,copper (Cu) layer 20, resist layer 22, and base 124 shown in FIG. 2E,and the method of fabrication is the same as shown in FIGS. 1A to 2E,description is omitted here.

In this basic art, as shown in FIG. 5A, a thin solder 126 is formed byplating on the base 124, and the resist layer 122 is removed, as shownin FIG. 69. Furthermore, with the thin solder 126 as a resist, as shownin FIG. 6C the copper (Cu) layer 120 is etched.

Next, as shown in FIG. 7A a solder resist layer 128 is formed over thewhole surface of the wafer 110, and as shown in FIG. 7B, the solderresist layer 128 in the region of the base 124 is removed by exposure,development, and firing processes.

Next, as shown in FIG. 7C, on the base 124 where the thin solder 126remains, a thick solder 129, thicker than the thin solder 126 is formedby plating. This is carried out by electroless plating. The thick solder129 is then subjected to wet-back whereby in the same manner as shown inFIG. 3, balls of at least hemispherical shape are formed. In this way,the thick solder 129 forms the solder balls of the external electrodes 5(see FIG. 5). The subsequent process is the same as in the first basicart described above.

According to this basic art again, almost all steps can be carried outwithin the stage of wafer processing. It should be noted that in thisbasic art, the thick solder 129 is formed by electroless plating. As aresult, the base 124 may equally be omitted, and the thick solder 129formed directly on the copper (Cu) layer 120.

(Third Basic Art)

FIGS. 8A to 9D illustrate the third basic art of the method of making asemiconductor device.

Since the wafer 30, electrodes 32, resin layer 34, chromium (Cr) layer36, copper (Cu) layer 40 and resist layer 42 shown in FIG. 8A are thesame as the wafer 10, electrodes 12, resin layer 14, chromium (Cr) layer16, copper (Cu) layer 20, and resist layer 22 shown in FIG. 2C, and themethod of fabrication is the same as shown in FIGS. 1A to 2C,description is omitted here.

Next, a part of the resist layer 42 shown in FIG. 8A is removed byexposure, development, and firing processes. In more detail, as shown inFIG. 8B, only the resist layer 42 positioned over the chromium (Cr)layer 36 forming the wiring is left, and in other areas the resist layer42 is removed.

Next, the copper (Cu) layer 40 is etched and the resist layer 42 isremoved, so that as shown in FIG. 5C, the copper (Cu) layer 40 is leftonly on the chromium (Cr) layer 36. In this way, the wiring is formed asa two-layer construction from the chromium (Cr) layer 36 and copper (Cu)layer 40.

Next, as shown in FIG. 80, a photosensitive solder resist is applied,and a solder resist layer 44 is formed.

As shown in FIG. 9A, in the solder resist layer 44 are formed contactholes 44 a. The contact holes 44 a are formed over the resin layer 34and over the copper (Cu) layer 40 which is the surface layer of thetwo-layer wiring. It should be noted that the formation of the contactholes 44 a is carried out by exposure, development, and firingprocesses. Alternatively, the solder resist may be printed leaving holesin predetermined positions so as to form the contact holes 44 a.

Next, a solder cream 46 is printed in the contact holes 44 a to form araised shape (see FIG. 9B). The solder cream 46 is formed into solderballs by a wet-back process as shown in FIG. 9C. Next, dicing is carriedout, and the individual semiconductor devices shown in FIG. 9D areobtained.

In this basic art, the base for the solder balls is omitted, andprinting of a solder cream is used, simplifying the formation of thesolder balls, and also reducing the number of steps in the fabricationprocess.

Besides, the wiring of the fabricated semiconductor device is two-layer,of chromium (Cr) and copper (Cu). Here, chromium (Cr) has good adhesionwith respect to the resin layer 34 formed of polyimide resin, and thecopper (Cu) has good resistance to cracks. The good resistance to cracksallows wire breaks and damage to the electrodes 32 or active elements tobe prevented. Alternatively, a copper (Cu) and gold two-layer, chromiumand gold two-layer, or chromium, copper (Cu), and gold three-layerwiring construction is also possible.

This basic art is an example of not using a base, however, it is evidentthat a base may be provided.

(Fourth Basic Art)

FIG. 10 illustrates the fourth basic art of the method of making asemiconductor device.

Since the wafer 130, electrodes 132, resin layer 134, chromium (Cr)layer 136, copper (Cu) layer 140 and solder resist layer 144 shown inthis figure are the same as the wafer 30, electrodes 32, resin layer 34,chromium (Cr) layer 36, copper (Cu) layer 40 and solder resist layer 44shown in FIG. 9A, and the method of fabrication is the same as-shown inFIGS. 8A to 9A, description is omitted here.

In this basic art, in place of the solder cream 46 used in FIG. 9B, flux146 is applied to the contact holes 144 a formed in the solder resistlayer 144 and solder balls 148 are disposed thereon. Thereafter, awet-back process, inspection, stamping, and dicing processes are carriedout.

According to this basic art, the preformed solder balls 148 are put inplace to be the external electrodes 5 (see FIG. 5). Besides, comparedwith the first and second basic arts, the base 24 or 124 can be omitted.Furthermore, the wires 3 (see FIG. 5) are of a two-layer construction,of the chromium (Cr) layer 136 and copper (Cu) layer 140.

This basic art is an example of not using a base, however, it is evidentthat a base may be provided.

(Fifth Basic Art)

FIGS. 11A to 12C illustrate the fifth basic art of the method of makinga semiconductor device.

First, as shown in FIG. 11A, a glass plate 54 is adhered to a wafer 50having electrodes 52. In the glass plate 54 are formed holes 54 acorresponding to the electrodes 52 of the wafer 50, and an adhesive 56is applied.

The coefficient of thermal expansion of the glass plate 54 has a valuebetween the coefficient of thermal expansion of the wafer 54 forming thesemiconductor chip and the coefficient of thermal expansion of thecircuit board on which the semiconductor device is mounted. Because ofthis, since the coefficient of thermal expansion varies in the orderfrom the semiconductor chip obtained by dicing of the wafer 54, theglass plate 54, and the circuit board (not shown in the drawings) onwhich the semiconductor device is mounted, the differences in thecoefficient of thermal expansion at the junctions is reduced, and thethermal stress is reduced. That is to say, the glass plate 54 acts asthe stress relieving layer. It should be noted that in place of theglass plate 54 a ceramic plate may also be used, provided that it has asimilar coefficient of thermal expansion.

Then, when the glass plate 54 is adhered to the wafer 50, adhesive 56which has entered the holes 54 is removed by an O₂ plasma process, asshown in FIG. 119.

Next, as shown in FIG. 11C, on the glass plate 54, being the wholesurface of the wafer 50, an aluminum layer 58 is formed by sputtering.Thereafter, if a film is formed on the surface of the hole(s) 54 thealuminum, which is susceptible to wire breaks, can be protected. Next,as shown in FIG. 12A a resist layer 59 is formed, and as shown in FIG.12B, exposure, development, and firing processes are used to remove apart of the resist layer 59. The part of the resist layer 59 removed ispreferably the area other than the portion where the wiring pattern isformed.

In FIG. 12B, the resist layer 59 is left extending from over theelectrodes 52 to over the glass plate 54. Besides, it is separated so asnot to connect from over one electrode 52 to over another electrode 52.

Next, when the aluminum layer 58 is etched, as shown in FIG. 12C, thealuminum layer 58 is left in the region to form the wiring. That is tosay, the aluminum layer 58 extends from the electrodes 52 over the glassplate 54 to form the wiring. Besides, the aluminum layer 58 is formed sothat individual electrodes 52 are not electrically connected to eachother, and the wiring is provided for each electrode 52 separately.Alternatively, if it is necessary for a plurality of electrodes 52 to beelectrically connected together, the aluminum layer 58 may be formed soas to provide the corresponding wiring. It should be noted that for thewiring, in place of the aluminum layer 58, any of the materials selectedin the first basic art may also be applied.

By means of the above process, since the wiring from the electrodes 52is formed, solder balls are formed on the aluminum layer 58 being thewiring, and individual semiconductor devices are cut from the wafer 50.These steps can be carried out in the same way as in the first basicart.

According to this basic art, the glass plate 54 has holes 54 a, but theformation of the holes 54 a is easy. Therefore, with respect to theglass plate 54 patterning beforehand to form bumps or wiring is notnecessary. Besides, for the steps, such as that of forming the aluminumlayer 58 being the wiring, technology of forming a metal thin film inwafer processing is applied, and almost all steps are completed withinthe stage of water processing.

It should be noted that on the glass plate 54, a separate stressabsorbing layer, such as polyimide resin, may be provided as in thefirst basic art. In this case, since the stress absorbing layer is onceagain provided, the coefficient of thermal expansion of the glass plate54 may be the same as that of silicon.

(Sixth Basic Art)

FIGS. 13A to 13D illustrate the sixth basic art of the method of makinga semiconductor device. In this example, a polyimide plate is selectedas the stress relieving layer. This is because polyimide has a lowYoung's modulus, and is therefore a suitable material for the stressrelieving layer. It should be noted that alternatively, for example, aplastic plate or glass epoxy or similar Composite plate may be used. Inthis case, it is preferable to use the same material as the mountingboard whereby the difference in the coefficient of thermal expansion isremoved. In particular, since at present the use of a plastic substrateas the mounting board is common, it is effective to use a plastic plateas the stress relieving layer.

First, as shown in FIG. 13A, a polyimide plate 64 is adhered to a wafer60 having electrodes 62, as shown in FIG. 13B. It should be noted thatan adhesive 66 has been previously applied to the polyimide plate 64.

Next, as shown in FIG. 13C, in the region corresponding to theelectrodes 62, contact holes 64 a are formed, using for example anexcimer laser, and as shown in FIG. 13D, an aluminum layer 58 is formedby sputtering. It should be noted that in place of the aluminum layer68, any of the materials selected in the first basic art may also beapplied.

In this way, the same state as shown in FIG. 11C is reached, andtherefore thereafter by carrying out the steps in FIG. 12A andsubsequent figures, the semiconductor device can be fabricated.

According to this basic art, since a polyimide plate 64 without even anyholes being formed is used, a patterned substrate is not required. Otherbenefits are the same as for the first to fifth basic arts describedabove.

As another basic art, the stress relieving layer may have holes formedmechanically by predrilling or similar means, and a positioning processmay be used for subsequent alignment on the wafer. It is also possibleto provide the holes by non-mechanical means, such as chemical etchingor dry etching. It should be noted that if holes are formed by chemicaletching or dry etching, this may be carried out on the wafer in aprevious preparatory step.

First Embodiment

The present invention seeks to further improve on the above describedbasic art, and the present invention is now described in terms of anumber of preferred embodiments, with reference to the drawings.

FIGS. 14A to 14D illustrate a first embodiment of the present invention.

In the semiconductor device 150 shown in FIG. 14A, a resin layer 152 ofpolyimide is formed discontinuously. The resin layer 152 forms a stressrelieving layer. As a stress relieving layer, photosensitive polyimideresin is preferable, but a nonphotosensitive resin may also be used. Amaterial such as a silicone denatured polyimide resin, an epoxy resin,or a silicone denatured epoxy resin that has a stress relieving functionhaving a low Young's modulus (not exceeding 1×10¹⁰ Pa) when solidifiedmay be used.

Besides, in the resin layer 152 is formed a tapered depression 152 a.Then wiring 154 is formed along the surface shape of the depression 152a, as a result of which, the wiring 154 is bent in cross-section. Itshould be noted that on the wiring 154 is formed a solder ball 157. Inthis way, as the wiring 154 is laid out on the resin layer 152 whichacts as a stress relieving layer, and being bent, it expands andcontracts more easily than if simply flat. Therefore, when thesemiconductor device 150 is mounted on a circuit board, the stressesgenerated by differences in the coefficient of thermal expansion can bemore easily absorbed. From the position where the wiring 154 isdisplaced (the bent portion and the like) to the solder ball 157, it ispreferable that as the resin layer 152 is selected a material with alarger elastic deformation ratio. This point applies in common to thefollowing embodiments.

Further, over the depression 152 a, or more precisely in the wiringregion formed in a depression in a position corresponding to thedepression 152 a, as shown in FIG. 14A, it is preferable for an elasticbody 156 to be provided. The elastic body 156 may be formed of thematerial used for the resin layer 152 forming the stress relievinglayer. By means of this elastic body 156, the stress of the expansionand contraction of the wiring 154 can be further absorbed. The functionof the elastic body 156 may be combined with the outermost layer(protective layer) formed by, for example, photoresist. Besides, theelastic body 156 may be provided separately for each depression 152 a.

In this way, breaks in the wiring 154 are prevented, and also damage toelectrodes 158 and the like by stress transmitted through the wiring 154is prevented. It should be noted that the electrodes 158 and wiring 154are protected by being covered by the outermost layer (protective layer)155.

Next, in the semiconductor device 160 shown in FIG. 14B, on the portionof first wiring 164 formed from an electrode 169 over a first resinlayer 162 which is over the first resin layer 162, a second resin layer166 and second wiring 168 are formed. The first wiring 164 is connectedto the electrode 169 and the second wiring 168 is connected to the firstwiring 164, and on the second wiring 168 is formed a solder ball 167. Inthis way, by forming a multi-layer structure of resin layers and wiring,the flexibility of wiring design is increased. It should be noted thatthe electrode 169 and wiring 164 and 168 are protected by being coveredby the outermost layer (protective layer) 165.

Further, wiring fine enough to have a negligible area may be formed witha planar enlargement (width or size). Besides, when the resin layerconsists of a plurality of layers the stress can be more easilydistributed. If the wiring given a planar form is at ground potential orpower supply potential, impedance control is made easier, and highfrequency characteristics are excellent.

Next, the semiconductor device 170 shown in FIG. 14C is a combination ofthe above described semiconductor devices 150 and 160. That is to say,on a first resin layer 172 is formed first wiring 174, and on the firstwiring 174, a second resin layer 176 is formed so as to have adepression 176 a. Then second wiring 178 formed on the second resinlayer 176 is formed so as to have a bent shape in cross-section. Itshould be noted that on the second wiring 179 is formed a solder ball177. Besides, an electrode 179 and wiring 174 and 178 are protected bybeing covered by the outermost layer (protective layer) 175. Accordingto this embodiment, the combined advantage of the above describedsemiconductor devices 150 and 160 is achieved.

Next, in the semiconductor device 180 shown in FIG. 14D, on a stressrelieving layer 187 formed in the region shown by a broken line, wiring184 is formed to be bent in a planar form from an electrode 182, and onthe wiring 184 is formed a bump 186 as a solder ball or the like. Inthis embodiment also, although the orientation is different from that ofthe above described semiconductor device 150 (see FIG. 14A), since thewiring 184 is bent, it has excellent stress absorbing ability.

It should be noted that the wiring 184 shown in FIG. 14D as bent in theplane may equally be bent in relief, as shown in FIGS. 14A to 14C. Bydoing this, the effectiveness for preventing wire breakages is evenfurther increased. However, it is essential that the stress relievinglayer 187 is present under the wiring 184. Besides, electrode 182 andwiring 184 are protected by being covered by the outermost layer(protective layer) not shown in the drawing.

Second Embodiment

Next, the semiconductor device 190 shown in FIG. 15 is characterized bywiring 200 connecting an aluminum pad 192 and a solder ball 196 providedon a stress relieving layer 194. For the wiring 200 may be used any ofthe wiring materials selected for the first basic art and the like. Thiswiring 200 has a bellows-like portion 200 a. The bellows-like portion200 a, as shown in FIG. 14D, is in a state that wire includes a slit anda plurality of the bellows-like portion 200 a is continuously formedbetween normal wiring. The bellows-like portion 200 a has betterstress-absorbing properties than the bent wiring 184. By the provisionof the bellows-like portion 200 a, the occurrence of cracks in thewiring 200 on the semiconductor chip, and damage to the aluminum pad 192and other active elements is eliminated, and the reliability of thesemiconductor device is increased. Besides, since the bellows-likeportion 200 a is provided in a single wiring, the space required for thestress absorbing construction is very small. By this means, thesemiconductor device can be kept compact, remaining in the CSP category,while the design freedom can be increased. It should be noted that inthis embodiment, the bellows-like portion 200 a is provided in thehorizontal plane direction, but equally this may be provided in thethickness direction.

In the above described embodiments and basic art solder has been givenas an example for the external electrodes, but as other examples, goldbumps may be used, or any other materials well known in the art may beused without any problem. Besides, external electrodes may be formedanywhere on the active surface of the semiconductor chip as long as theyare not over the electrodes.

Third Embodiment

FIGS. 16 to 20 show a third embodiment of the present invention. FIG. 16shows a cross-section of the semiconductor device of this embodiment. Asemiconductor device 300 has a semiconductor chip 302 on which is amulti-layer structure (four layers), and the surface being protected bya solder resist 350. It should be noted that in this embodiment also,materials and manufacturing method, and so on described in otherembodiments and in the basic art, may also be applied.

FIGS. 17A and 17B show the first layer. In more detail, FIG. 17B is aplan view and FIG. 17A is a cross-sectional view along the line VII-VIIin FIG. 17B. The semiconductor chip 302 has an electrode 304 whichinputs or outputs a signal. A stress relieving layer 310 is formed to beinclined at the end thereof, in the vicinity of the electrode. Thestress relieving layer 310 is an insulator, and in particular apolyimide resin is preferable. Next, signal wiring 312 is formed fromthe electrode 304 to over the stress relieving layer 310. The signalwiring 312, as shown in FIG. 17B, has a connection portion 312 a in theform of an island at the end opposite to the electrode 304. Besides,surrounding this connection portion 312 a but not coming into contacttherewith is formed a ground plane 316. The ground plane 316 isconnected to a grounding electrode (not shown in the drawing) of thesemiconductor chip 302.

FIGS. 18A and 18B show the second layer. In more detail, FIG. 18B is aplan view and FIG. 18A is a cross-sectional view along the lineVIII-VIII in FIG. 18B. As shown in these figures, a stress relievinglayer 320 is formed over the first layer described above. However, thestress relieving layer 320 is formed so as to avoid the center portionof the connection portion 312 a of the signal wiring 312 of the firstlayer. Then signal wiring 322 is formed from the connection portion 312a of the first layer to over the stress relieving layer 320 for thesecond layer. The signal wiring 322 has a connection portion 322 aconnecting to the connection portion 312 a, and another connectionportion 322 b. Besides, on the stress relieving layer 320 is formedsignal wiring 324 not electrically connecting to the signal wiring 322.The signal wiring 324 has connection portions 324 a and 324 b. Furtheron the stress relieving layer 320 is formed other wiring 324 and 325,but this is not related to the present invention, and description isomitted here. Besides, surrounding signal wiring 322 and 324 and wiring324 and 325 but not coming into contact therewith is formed a groundplane 326. The ground plane 326 is connected to a grounding electrode(not shown in the drawing) of the semiconductor chip 302 through theground plane 316 of the first layer.

FIGS. 19A and 198 show the third layer. In more detail,

FIG. 19B is a plan view and FIG. 19A is a cross-sectional view along theline IX-IX in FIG. 19B. As shown in these figures, a stress relievinglayer 330 is formed over the second layer described above. However, thestress relieving layer 330 is formed so as to avoid the center portionof the connection portion 322 b of the signal wiring 322 of the secondlayer. Then signal wiring 332 is formed from the connection portion 322b of the second layer to over the stress relieving layer 330. The signalwiring 332 has a connection portion 332 a connecting to the second layerconnection portion 322 b, and another connection portion 332 b. Further,on the stress relieving layer 330 is formed signal wiring 334 notelectrically connecting to the signal wiring 332. The signal wiring 334has connection portions 334 a and 334 b. Besides, surrounding signalwiring 332 and 334 but not coming into contact therewith is formed aground plane 336. The ground plane 336 is connected to a groundingelectrode (not shown in the drawing) of the semiconductor chip 302through the ground plane 316 of the first layer and the ground plane 326of the second layer.

FIGS. 20A and 20B show the fourth layer. In more detail, FIG. 20B is aplan view and FIG. 20A is a cross-sectional view along the line X-X inFIG. 20B. As shown in these figures, a stress relieving layer 340 isformed over the third layer described above. However, the stressrelieving layer 340 is formed so as to avoid the center portion of theconnection portion 334 b of the signal wiring 334 of the third layer.Then a connection portion 342 is formed over the connection portion 334b of the third layer, and on this connection portion 342 is formed abase 344 of copper (Cu), and a solder ball 348 is formed on the base344. The solder ball 348 forms an external electrode. Besides,surrounding the connection portion 342 but not coming into contacttherewith is formed a ground plane 346. The ground plane 346 isconnected to a grounding electrode (not shown in the drawing) of thesemiconductor chip 302 through the ground plane 316 of the first layer,the ground plans 326 of the second layer, and the ground plane 336 ofthe third layer.

Next, the conductivity state of this embodiment is described. Theelectrode 304 formed on the semiconductor chip 302 is connected tosignal wiring 312 of the first layer, and this signal wiring 312 isconnected to signal wiring 322 of the second layer. This signal wiring322 is connected through its connection portion 322 b to signal wiring332 of the third layer, and this signal wiring 332 is connected throughits connection portion 332 b to signal wiring 324 of the second layer.The signal wiring 324 is connected through its connection portion 324 bto signal wiring 334 of the third layer. Then the solder ball 348 isformed at the connection portion 334 b, with the connection portion 342and base 344 interposed therebetween.

In this way, the electrode 304 formed at a certain position on thesemiconductor chip for the purpose of inputting or outputting a signalis connected to the solder ball 348 which acts as an external electrodeformed at a certain position on the semiconductor chip.

Naturally, as mentioned in the other embodiments and basic art, theexternal electrodes may be disposed in a matrix.

Besides, the ground planes 316, 326, 336, and 346 of the first to fourthlayers are all at the same ground potential.

Therefore, according to this embodiment, the wiring between theelectrode 304 and the solder ball 345 is surrounded by conductors atground potential, with insulation interposed therebetween. In otherwords, the internal conductor is surrounded by external conductors atground potential, with insulation interposed therebetween, thus such aconstruction is the same as that of coaxial cable. By this means,signals are less susceptible to the influence of noise, and an idealtransmission path is obtained. Also, for example, if the semiconductordevice is a CPU, high-frequency operation, exceeding 1 GHz, is Possible.

It should be noted that in order to reduce the cost of fabricating thelayers, either of the ground planes 316 and 346 formed in the first andfourth layers may be omitted.

Other Embodiments

The present invention is not restricted to the above describedembodiments, and various modifications are possible. For example, theabove described embodiments apply the present invention to asemiconductor device, but the present invention can be applied tovarious electronic components for surface mounting, whether active orpassive.

FIG. 21 shows an example of a electronic component for surface mountingto which the present invention is applied. In this figure, an electroniccomponent 400 has a chip portion 402 at both ends of which are providedelectrodes 404, and for example, this may be a resistor, capacitor,coil, oscillator, filter, temperature sensor, thermistor, varistor,variable resistor, or fuse. The electrodes 404 have wiring 408 formedwith a stress relieving layer 406 interposed therebetween, in the sameway as in the embodiments described above. On this wiring 40 a, bumps410 are formed.

Besides, FIG. 22 also shows an example of a electronic component forsurface mounting to which the present invention is applied. Thiselectronic component 420 has electrodes 424 formed on the mountingsurface of a chip portion 422, and wiring 42 a formed with a stressrelieving layer 426 interposed. On this wiring 428, bumps 430 areformed.

It should be noted that the method of fabrication of these electroniccomponents 400 and 420 is the same as in the above described embodimentsand basic art, and therefore description is omitted here. Besides,benefit obtained by formation of the stress relieving layers 406 and 426is the same as in the above described embodiments and basic art.

Next, FIG. 23 shows an example in which a protective layer is formed ona semiconductor device to which the present invention is applied. Asemiconductor device 440 shown in this figure is the semiconductordevice shown in FIG. 4C on which a protective layer 442 is formed, andsince this is the same as the semiconductor device shown in FIG. 4Cexcept for the protective layer 442, description is omitted here.

The protective layer 442 of the semiconductor device 440 is formed onthe side opposite to the mounting surface, that is to say, on the rearsurface. By so doing, the rear surface can be protected from damage.

Furthermore, damage to the semiconductor chip itself caused by cracksinitiated by damage to the rear surface can be prevented.

The protective layer 442 is preferably formed on the rear surface of thewafer before cutting into individual semiconductor devices 440. If thisis done, a plurality of semiconductor devices 440 can have theprotective layer 442 formed simultaneously. In more detail, it ispreferable that after the process of forming a metal thin film iscompleted, the protective layer 442 is formed on the wafer. By so doing,the process of forming a metal thin film can be carried out smoothly.

The protective layer 442 is preferably of a material which can withstandthe high temperature of the reflow process of the semiconductor device440. In more detail, it is preferable that it can withstand thetemperature which is the melting point of the solder. Besides, theprotective layer 442 may be formed by application of a potting resin.Alternatively, the protective layer 442 may be formed by attaching asheet having either tackiness or adhesion. This sheet may be eitherorganic or inorganic.

In this way, since the surface of the semiconductor device is coveredwith a substance other than silicon, for example, the marking qualitiesare improved.

Next, FIG. 24 shows an example in which a radiator is fitted to asemiconductor device to which the present invention is applied. Asemiconductor device 450 shown in this figure is the semiconductordevice shown in FIG. 4C to which a radiator 452 is fitted, and sinceexcept for the radiator 452 this is the same as the semiconductor deviceshown in FIG. 4C, description is omitted here.

The radiator 452 on the semiconductor device 450 is formed on the sideopposite to the mounting surface, that is to say, on the rear surface,with a thermally conducting adhesive 454 interposed. By so doing, theheat radiation properties are improved. The radiator 452 has a pluralityof fins 456, and these are commonly formed of copper, copper alloy,aluminum nitride, or the like. It should be noted that in this example,an example with fins is shown, but a radiation (plate radiator) withoutfins may also be used to obtain an appropriate radiation effect. In thiscase, since a plate is simply attached, the handling is easy, and thecost can also be reduced.

In the above described embodiments and basic art, solder bumps or goldbumps are provided in advance as external terminals on the semiconductordevice, but as other examples, without using solder bumps or gold bumpson the semiconductor device, for example, a base itself of copper or thelike may be used for an external terminal. It should be noted that inthis case, it is necessary to provide solder on the connecting portion(land) of the semiconductor device on the mounting board (motherboard)on which it is mounted before the semiconductor device is mounted.

Besides, the polyimide resin used in the above described embodiments ispreferably black. By using a black polyimide resin as the stressrelieving layer, operating faults when light impinges on thesemiconductor chip can be avoided, and also with an increase in thedurability with respect to light the reliability of the semiconductordevice car also be improved.

In FIG. 25 is shown a circuit board 1000 on which is mounted anelectronic component 1100 such as a semiconductor device fabricatedaccording to the methods of the above described embodiments. Moreover,as an electronic instrument provided with this circuit board 1000, FIG.26 shows a notebook personal computer 1200.

1. A semiconductor device comprising: a semiconductor chip that has afirst electrode; a first resin layer that is provided on thesemiconductor chip, the first resin layer being formed with aninclination at an edge of the first resin layer; a first conductingportion that extends from the first electrode to the first resin layer,the first conducting portion having a first portion, a second portion, athird portion and a fourth portion, the first portion and the secondportion being disposed on the first resin layer, the first portionextending along a first virtual straight line in a plane parallel to afirst surface of the semiconductor chip on which the first electrode isformed, the second portion extending along a second virtual straightline in the plane, the second virtual straight line being different fromthe first virtual straight line and the second virtual straight line andthe first virtual straight line being non-collinear, the first portionand the second portion being in straight form, the fourth portion beingarranged between the first portion and the second portion and bending inthe plane, the third portion disposed on at least a part of theinclination, the third portion extending from the first electrode to anend of a curved connecting portion between an end of the third portionand an end of the first portion along a third virtual straight line andextending on a part of the third virtual straight line, the thirdvirtual straight line intersecting the first virtual straight line andthe second virtual straight line as viewed from above the firstconducting portion, the second portion crossing the third virtualstraight line, and the first virtual straight line and the secondvirtual straight line are not parallel to the third virtual straightline; a second resin layer that is provided on the first resin layer; asecond conducting portion that is provided on the second resin layer, aplanar extent of the second conducting portion being larger than that ofthe first conducting portion; and a second electrode that iselectrically connected to the first conducting portion, the secondelectrode being formed above the first resin layer.
 2. The semiconductordevice according to claim 1, wherein the first portion and the secondportion are positioned between the first electrode and the secondelectrode.
 3. The semiconductor device according to claim 1, wherein thefirst resin has a depression, and an elastic is provided so as to fillthe depression.
 4. The semiconductor device according to claim 1,wherein the first conducting portion is formed to have bellows form. 5.The semiconductor device according to claim 1, wherein the firstconducting portion is formed in linear form, and the second conductingportion is formed in planar form.
 6. The semiconductor device accordingto claim 1, wherein the second conducting portion has ground potential,and a signal is inputted in the first conducting portion.
 7. Thesemiconductor device according to claim 1, further comprising: a pair ofwires at ground potential formed parallel to and on both sides of thefirst conducting portion.
 8. The semiconductor device according to claim1, wherein the first conducting portion is formed to be bent in thethird virtual straight line crossing the first surface of thesemiconductor chip.
 9. The semiconductor device according to claim 1,wherein the second conducting portion is provided above the firstconducting portion.
 10. The semiconductor device according to claim 1,wherein the first portion and the second portion are substantiallyparallel.
 11. A semiconductor device comprising: a semiconductor chipthat has a first electrode; a first resin layer that is provided on thesemiconductor chip, the first resin layer being formed with aninclination at an edge of the first resin layer; a first conductingportion that extends from the first electrode to the first resin layer,the first conducting portion having a first portion, a second portion, athird portion and a fourth portion, the first portion and the secondportion being disposed on the first resin layer, the first portionextending along a first virtual straight line in a plane parallel to afirst surface of the semiconductor chip on which the first electrode isformed, the second portion extending along a second virtual straightline in the plane, the second virtual straight line being different fromthe first virtual straight line and the second virtual straight line andthe first virtual straight line being non-collinear, the first portionand the second portion being in straight form, the fourth portion beingarranged between the first portion and the second portion and bending inthe plane, the third portion disposed on at least a part of theinclination, the third portion extending from the first electrode to anend of a curved connecting portion between an end of the third portionand an end of the first portion along a third virtual straight line andextending on a part of the third virtual straight line, the thirdvirtual straight line intersecting the first virtual straight line andthe second virtual straight line as viewed from above the firstconducting portion, the second portion crossing the third virtualstraight line, and the first virtual straight line and the secondvirtual straight line are not parallel to the third virtual straightline; and a second electrode that is electrically connected to the firstconducting portion, the second electrode being formed above the firstresin layer.
 12. The semiconductor device according to claim 11, whereinthe first conducting portion has a fifth portion and a sixth portion,wherein the sixth portion is in straight form, and wherein the fifthportion is arranged between the second portion and the sixth portion andbent in the plane.
 13. The semiconductor device according to claim 12,wherein the first conducting portion has a seventh portion and a eighthportion, wherein the second electrode is disposed on the eighth portion,wherein the seventh portion is arranged between the sixth portion andthe eighth portion.